1. Field of the Invention
The present invention generally relates to an information recording/reproducing device and a method of recording a lead-out on an information recording medium. The present invention is applicable to information recording/reproducing devices for recording data on an information recording medium exchangeable in a computer system, such as optical disks like CD-R/RW, DVD-R/RW, DVD+RW/R, magneto-optical disks like MO, magnetic disks such as HD, FD, and memory cards. The present invention is applicable to information recording/reproducing devices that can eject an information recording medium during a process of background formatting. The present invention is also applicable to information recording/reproducing devices that can record a lead-out on an lead-out area on an information recording medium.
2. Description of the Related Art
There is a UDF (Universal Disc Format) system in file systems using information recording media. The UDF is employed in various devices. The recording format of the UDF can make full use of characteristics of various devices. Especially, since CD-RW or DVD+RW is capable of overwriting data, they employ the UDF that allows random recording/reproducing of data.
In the case of CD-RW, in order to record/reproduce data randomly, it is necessary to previously format the medium by recording dummy data on the whole or partial area of the medium. And also in the case of DVD+RW/-RW, it is necessary to record dummy data on the unrecorded area until some radial distance is reached, if compatibility with conventional DVD-ROM drives is required.
Further, as for CD-R/DVD-R/DVD+R as a write-once medium, although there is no formatting operation, continuous recording without an unrecorded area is needed, if compatibility with reproducing devices is to be attained. In this case, it is necessary to record something on the unrecorded area to indicate recording completion. This area is called a lead-out area.
In the above formatting process, because dummy data are recorded over the whole or designated partial area of the information recording medium, time required for formatting increases proportionally to increased capacity of the information recording medium.
In order to solve this problem, Japanese Patent Laid-open Publication No. 11-134799 “Optical disk recording/reproducing device, optical disk recording/reproducing method and computer readable recording medium” proposes an information recording/reproducing device, in which a formatting process is performed in background mode and data recording/reproducing can be carried out in a short time at user's request. Although the technology disclosed in the publication relates to background formatting for a CD-RW disk, background formatting for a DVD+RW disk is also proposed.
In the background formatting process, an unrecorded area or unformatted area is filled with dummy data during periods when no user request for data recording/reproducing is made. During the background formatting process, if a user makes a request for data recording/reproducing, then the formatting process is interrupted and data recording/reproducing begins. In this way, during the background formatting process, it is necessary to perform data recording/reproducing requested by a user and perform dummy data recording in background mode in parallel.
And during the background formatting process, it is possible for a user to remove the information recording medium from the information recording/reproducing device before completing the formatting. When removing the information recording medium, a temporary lead-out is recorded following data recording area, to allow the removed disk to be read by conventional DVD-ROM drives. The temporary lead-out indicates or marks the extent to which data have been recorded on the information recording medium. The temporary lead-out can prevent a pickup (recording/reproducing head) from unnecessarily moving to an unrecorded area and protect its optical system. The temporary lead-out needs to be of large size to some extent, because it relates to the physical operation of the device.
The temporary lead-out begins its recording at the final address in the outer radial area where the background formatting or user data recording has been completed. As for an information recording medium on which the temporary lead-out is recorded, it is possible to resume formatting from the temporary lead-out starting position at a user's request.
As mentioned above, in the conventional information recording/reproducing devices, it is possible for a user to record and reproduce data at any area during the background formatting. And it is also possible for a user to remove the disk during the background formatting. When removing the disk from the drive before completing the background formatting process, if a temporary lead-out is recorded before removing, then the disk becomes readable by conventional CD-ROM/DVD-ROM drives. The temporary lead-out is recorded following the background formatted area or data recorded area at the user's request.
However, recording such a lead-out takes a long time and consumes a large data area. And it is understood that compatibility with various CD/DVD players, recorders or other information recording/reproducing devices available in the market-place depends on the length of the lead-out. Consideration of the above situation has resulted in the present invention.